I. Field of the Invention
The present invention relates generally to key cutting machines. More particularly, the present invention relates to a key cutting machine capable of reproducing a pattern key onto a key blank while eliminating the wear and miscutting of the pattern key, thereby utilizing the advantages of key machines which operate by code operations.
II. Description of the Relevant Art
In a key cutting machine, conventional methods of cutting are old and well-known. There are presently known two types of cutting devices.
The first type utilizes a pair of vices, one for the pattern key and one for the key blank. A stylus is used to follow along the contour of the pattern key and reproduce the contour of the pattern key onto the key blank either by moving a cutter to notch the key blank or by moving the key blank to the cutter.
The second type utilizes a code system and a key blank. Rather than duplicating a key from a pattern, the code system cuts a key based upon known information including the depth and spacing of the serrated edge or edges. The code system may either be computer coded or coded from a card or a plate. A card system is disclosed in U.S. Pat. No. 4,188,163 issued in 1980 to Juskevic and entitled "KEY DUPLICATING MACHINE".
The first type suffers from known disadvantages. First, the copied key duplicates the pattern key exactly, and accordingly includes any copy errors or wear preset in the pattern key. Second, because the stylus follows the serrations with relative exactness, chatter (cutting) marks appear on the copied key. Both of these disadvantages result in poor lock operation and premature wear of the lock components.
The second type, while eliminating some problems of the first method, is impractical for general use in that it cannot copy a pattern key. This method is more properly suited for originating a key without a pattern.
Accordingly, prior inventions have failed to overcome the known disadvantages of duplicating machines.